WASHINGTON — President Reagan, turning aside pleas of the civil rights community and GOP political strategists, will veto major civil rights legislation and offer his own more narrowly drawn alternative, the White House said Tuesday.

Presidential spokesman Marlin Fitzwater confirmed Reagan would veto the Civil Rights Restoration Act, which would overturn the 1984 Supreme Court decision in the case of Grove City vs. Bell. That court ruling sharply limited the reach of federal anti-discrimination sanctions at colleges and universities.

''The president has always believed that the Grove City decision was a mistake and that the non-discrimination protections that were available before that decision should be restored,'' Fitzwater said.

''I think we have a very positive alternative bill that overturns the Grove City decision and also lays out our civil rights objectives in these areas and states the very important civil rights principles that we think need to be restored in terms of preventing discrimination,'' he said.

In the Grove City decision, the high court said the government could not use the receipt of federal funds by a single department to bring discrimination charges against an entire university or programs not receiving federal grants.

The bill, which has languished in Congress for almost four years in a dispute over abortion, passed the Senate Jan. 28 on a 75 to 14 vote and was approved by the House March 2 with a 315 to 98 vote.

Reagan's new proposal is expected to be similar to a GOP substitute defeated by the House before passage of the bill now before Reagan. Although Fitzwater speculated the alternative could prove attractive to ''a large number'' of lawmakers, the bill on his desk passed both chambers by margins large enough to raise the threat of a veto override.

In standing firm on his decision to veto the bill, Reagan turned aside pleas from such groups as the U.S. Catholic Conference, which earlier in the day urged Reagan to sign the law.

Archbishop John May, president of the National Conference of Catholic Bishops, said in a letter to Reagan that the bill ''does much to strengthen civil rights protection while safeguarding vital concerns about human life and religious liberty.''